Three staff working in a Pakistani news agency were shot dead when two gunmen burst into their office in Quetta, south-west Pakistan.

One of the murdered trio was Irshad Mastoi (aka Arshad Mustoi), 34, secretary general of Balochistan Union of Journalists (BUJ). The others were trainee reporter Abdul Rasul and the agency's accountant, Mohammed Younus. All were reported by police to have died on the spot.

Mastoi, of the Online news network, wrote for local and national newspapers. Rasul, who was in his early 20s, was a student in his final year studying journalism Department at Balochistan university.

Mastoi had previously criticised the lack of security for journalists in Balochistan and that no perpetrator of any journalistic murder had been arrested.

Irfan Saeed, the BUJ president, said: "The gruesome attack saddened all the journalists. I do not have the words to express our grief."

Some months ago, Balochistan's chief minister, Dr Abdul Malik, said a judicial tribunal would be set up to investigate the killings of journalists in Balochistan. But, said Saeed, it has yet to be implemented, adding: "The killers are carrying out attacks with complete impunity."

In condemning the murders, the Pakistan newspaper editors' council described it as a conspiracy to curb the press and demanded action to find and arrest the culprits.

The attack on Online happened within hours of gunmen shooting six members of a minority Islamic sect (Zikris), and wounding seven others, while they were worshipping at a shrine in the Awaran district, about 650kms south-west of Quetta.